So I purchased some dwarf high grass from Petsmart about a week ago. It came as a 4 inch long by like 1 inch wide strip of grass with completely tangled roots. When I placed it in the tank it tried to float so I put in something to help hold it down. It's been about a week and it seems to be happy enough but not rooted into my sand cap so it can get to the soil. I looked around and found people saying that you should pull it apart and plant smaller bits but I'm afraid that that will weaken them. Should I get some large rocks to put around it to help hold it down better and let it root itself through the substrate? Should I pull it apart? What should I do?

I have been known to tie stubborn plants to pieces of driftwood, rocks, broken pieces of terracotta pots -- pretty much anything with some weight and surface area that can be pushed under or buried under gravel or sand. You can plant as it is, and let it naturally spread out, or you can pull it apart. Pulling it apart now can help you fill your tank a bit better, and you won't have to uproot it to separate it as soon as you would if you just planted it as-is. You can use sewing thred (non-metallic) or preferably fishing line to tie the bundles to whatever weight you choose. Hope that helps.